Georgian sash windows

It was not uncommon to find Georgian houses designed with sash windows. However, the arrangement used two sashes with panes arranged in a three by two-panel design. The six-pane window was the common platform, but these sashes were not limited to this design. Most Edwardian and Victorian suburban homes were designed using mass produced sash windowpanes measuring four feet in width. However, Georgian sashes of any size could be used because the design accounted for the hand-made imperfections.

This was done by balancing the glazed panel with steel, cast-iron or heavy lead sash counterweights that could be concealed within the window frame. A pulley, cotton cord or chain connected the sash weight to the top of the frame. The sash cords were one of the main causes of destruction or disassembly of windows to allow repair people to gain access to broken sash cords.

The look of sash windows was affected by two focal developments in the Georgian period. First was the invention and mass manufacture of crown glass. The crown glass made it possible to mould larger windowpanes. Now the sash windows only needed six panes creating the six-over-six sash window design now associated with the Georgian era.

Second was the development of a narrow glazing bar. Placing the masonry before the sash box was a regulation in the 1774 London Building Act. The law meant that wider glazed window areas could be made while keeping most sash boxes out of sight. The boxes were tucked behind the masonry leaving little timber visible. As a result, gaze bars became narrower to reduce the proportion of the sash box. Isaac Ware (1750) wrote that very little of the frame should be seen while as much glass as possible should be visible.